As commercial airplanes gain greater range capability and airlines schedule more long duration non-stop flights, there is an increasing demand for premium-class seating that allows passengers to sleep fully reclined, i.e., in a more normal, relaxing, horizontal position. Providing conventional forward-facing seating that reclines to a fully reclined position has certain obvious disadvantages. For example, the seats must be installed at a pitch, i.e., distance between corresponding points on the seats, exceeding the length of the tallest passenger likely encountered plus enough space for window seat passengers to gain access to the aisle when the seat closest to the aisle, i.e., the aisle seat, is fully reclined. Seat pitches on the order of 80 inches are becoming common for this use. Such seat pitches dramatically reduce seating capacity or seat count of the airplane and therefore reduce the revenue that may be generated by the airplane.
The problem of such inefficient space utilization is exacerbated by the fact that passengers are only interested in sleeping on some flight phases or segments and not during all portions of these segments. As an example, eastbound transatlantic flights are typically flown at night and most passengers are interested in sleeping once the meal service is completed. Westbound transatlantic flights by contrast are typically flown during daylight hours with little demand for sleeping facilities. No workable concept has been seen to configure airplanes differently for such westbound and eastbound flights.
Several concepts have been described or are in use to minimize the seat count loss resulting from fully reclinable seating. For example, some airlines have arranged seats in a herringbone or echelon fashion in the forward zone of the Boeing Model 747 (ref. British Patent GB 2,295,962 awarded to Dryburgh, et al.) This arrangement has resulted in a modest reduction of the seat count loss resulting from the installation of fully reclinable seats.
Another example is the provision of alternate sleeping facilities in portions of the airplane not typically used for passenger seating, e.g., in the lower (cargo) hold or above the passenger cabin ceiling. However, these provisions have not proven popular for several reasons. Lower hold installations may displace revenue-generating cargo and thus, have not, generally speaking, proven attractive. In most commercial airplanes there is no usable space above the passenger ceiling. In those airplanes in which space is available, it is of limited size--particularly height. Access to over-ceiling, as well as lower-hold, areas is also difficult. Finally it is believed that passengers do not like to be physically separated from their assigned seat, and the belongings stowed there, while sleeping.
Wide aisles, considerably wider than those required for emergency evacuation, are typically provided in intercontinental first and business-class ("high-yield") passenger cabins. The wider aisles provide ease of boarding and passenger mobility within the cabin while the meal service is in progress. More particularly, the Federal Aviation Administration requires a minimum of 15 inch aisles for passenger emergency evacuation. In contrast, typical first-class aisles in the Boeing Model 747 are 34 inches wide. In both the Boeing Model 777 first-class and in the Boeing Model 747 upper-deck business-class, aisles are 29 inches wide. From the time the dinner service is concluded until breakfast is served, the time when sleeping facilities are most needed ("nighttime"), such wide aisles are unnecessary. This space utilization cycle thus provides a business opportunity for airline owners and operators to increase the revenue generating capacity, and thus value, of their commercial airplanes. The passenger seat assemblies of the present invention completely satisfy this need of airline owners and operators.
In addition, the unique upper deck of the Boeing Model 747 has sloping sidewalls which render the space adjacent to the sidewalls of the interior of the airplane unusable for upright seating. The passenger seat assemblies of the present invention utilize under sidewall space in addition to aisle space to provide sleeping accommodations.